In my current home, I have two "heads" attached to a single outside unit, but they cannot operate independently beyond setting different fan speeds or closing the vent really. If one of the mini-splits is set to heat and the other switches to cooling, they will booth start cooling, or vice versa, the head units just blindly blow air over what ever is being pumped through the line and the last unit to send a command to switch mode "wins".

Maybe there are clever heat pumps that truly allow fully independent control of the head unit when connected to multiple heads, but given the flow of refrigerant has to reverse direction completely when switching between heating and cooling, I don't see how they can operate fully independently when they are sharing the same refrigerant lines.

There is only one reversing valve inside the outside unit for all the head units connected to one outside unit in my experience, but would love to see examples of systems that do permit this if they exist.

> https://en.wikipedia.org/wiki/Reversing_valve